Bono took a look around the cluttered recording studio, filled with Coke bottles and laptops and vinyl records, and turned to a reporter.

‘I’m not sure where we put the crack pipe,” he deadpanned, pretending to riffle around a coffee table as he also poked at the band’s workaholic image. “We usually leave it out for guests.”

A moment later the U2 frontman had cranked up a track from the band’s work-in-progress April album, an anthemic number about leaving one’s hometown titled “Invisible.” As the song played, he spiritedly played air guitar to it, also belting along with the track’s vocals, so that, in effect, Bono was performing a duet with himself.

The 53-year-old rock star’s self-mocking turn is enjoyably at odds with his self-serious public image, a sign of an icon who knows when not to be iconic. But similarly surprising is his approach to the music, a kind of boyish giddiness suggesting that, even after 12 studio albums and thousands of shows, that’s really what matters, perhaps more now than in a long while.

After years of being known as much for activism as rock ‘n’ roll — the day after the studio session, Nelson Mandela will have passed away, and an essay from Bono recollecting his impressions of the South African leader and friend will have materialized on Time.com — U2 had perhaps its most commercially disappointing album in decades with 2009′s “No Line on the Horizon.” They also worked on some aborted projects that led to just one new studio album in the past nine years. So now they’re shaking things up.

The band, which of course also includes guitarist Edge, bassist Adam Clayton and drummer Larry Mullen Jr., came up with the concept of a collection of songs told partly from the perspective of an innocent and partly from a seasoned veteran. And they brought on the electronic dance music producer Danger Mouse to help them craft it.